Expansible pulley.



. PATENTED MAY 14, 1907.

.G.J.REED. EXPANSIBLE PULLEY. APPLICATION FILED MAY 25, 1904.

|naaa:ummummmm iiiiiiiiiiiiilliiiiiiiilHil I ll y ll l l llllllllllllllllllllIllll I ill 'ma/emor,

'6' an! Z174,

THE NORRIS PETERS cm, wAsnma-mu, o c

- pinned to the pulley-shaft 5.

UNITED STATES PATENT FPICEQ CHARLES J. REED, OF PHILADELPHIA, PENNSYLVANIA, ASSIGN OR TO REED MORRILL ELECTRIC CO., A CORPORATION OF PENNSYLVANIA.

EXPANSIBLE PULLEY.

Specification of Letters Patent.

Patented May 14, 1907.

Application filed May 25,1904. Serial No. 209,723.

To all whom, it may concern:

Be it known that I, CHARLES J. REED, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Expansible Pulleys, of which the following is a specification.

In U. S. Patents Nos. 758,474 and 758,561, granted to me April 26, 1904, I have shown and claimed a mechanism for transmitting power from a driving to a driven shaft and enabling the speed of the driven shaft to be varied with reference to that of the driving shaft, comprising a double pulley placed between and belted to pulleys on the driving and the driven shafts. Each drum of the double pulley consists of a set of radiallyadjustable rim-sections, the ends of which pass through radial slots in circular guideplates and have teeth entering spiral grooves in circular adjusting disks. Differential gear-mechanism is provided to rotate the guide-plates with reference to the adjustingdisks, thereby simultaneously moving either set of rim-sections inwardly and the'other outwardly, contracting one drum and expanding the other. The shaft of the double pulley is carried by rock-arms, to compensate for changes in the working length of the belts by which it receives and transmits power.

The present invention relates to expansible pulleys, especially of the type shown in these patents, and specifically to stop-devices for positively limiting the travel of the rim-sections in the spiral grooves of the adjustingdisks when shifted to their outermost or innermost position.

Referring to the accompanying drawings: Figure 1 is a side elevation of a portion of a double pulley, with the parts above a horizontal axial plane in vertical axial section; and Fig. 2 is an end elevation of the pulley shown in Fig. 1, with a portion broken away.

The pulley which has been chosen to illustrate the invention has two drums 2 and 3. Between the drums is a rim-section-adjusting disk 4, spirally grooved on both faces, which is carried by and screwed to a collar 4 The other spirally-grooved adjusting-disk 6 of the drum 3 is keyed on the shaft. The rim-sections 7 have toothed ends which enter the spiral grooves of the disks. Each drum has two rim-section-guiding plates, the adjacent plates 8, 9 of the drums 2 and 3 being arranged on opposite sides of the double adjusting-disk 4 and rigidly connected at their edges by a rim 11. This rim, as in my specified patents, serves as a particular means for transmitting torque from any preferred gearing or mechanism employed to operate the rim-sections of the pulley, and therefore as a means for effecting the relative rotation of said plate and disk. The two guideplates 9, 10 of the drum 3 are screwed to the flanged ends of a sleeve 12 which is revolubly supported on the pulley-shaft between the adjusting-disks 4, 6. The grooves in the two adjusting-disks of each drum are parallel but in opposition to those of the other drum so that rotation of the guide-plates on the shaft simultaneously moves one set of rim-sections outwardly and the other inwardly.

The pulley-mechanism which has been described is substantially that of my specified patents. In constructing and operating these pulleys, I have found that when the rim-sections reach their outermost or innermost position, they are liable to be forcibly pressed against the ends of the radial guideslots by the wedging action of the spiral grooves. They thus bind between the guideplates and adj usting-disks and render it dificult to again rotate these with reference to each other. The present invention is a device or mechanism to stop the rotation of the guide-plates just before the rim-sections reach either end of the guide-slots. For this purpose the adjusting-disk 6 is provided with a long hub 13 on which are supported two parallel, oppositely-coiled strips 14, 15 of sheet-steel. The inner ends of both strips enter recesses in the hub 13 and are secured thereto by pins 16. The outer ends of the strips are secured to brackets 17 projecting from the outer face of the guide-plate 10 at its edge and on opposite sides of the shaft. The coiled strips are separated by a thin disk 18 and a similar disk 19, not shown in Fig. 2, is secured on the hub 13 outside the strip 15. The length and number of coils of each of these strips is such that rotation of the guide-plate 10 in either direction while uncoiling one strip tightly coils the other strip, which stops the rotation of the guide-plate just before the rim-sections reach either end of the radial slots. The coiled strip 15 serves to stop the inward movement of the rim-sections of the'dru'm 3 and the drawing shows these rim-sections in their innermost position, with the strip 15 tightly coiled. Rotation of the guide plate to move these rim-sections outward would uncoil the strip and coil up the strip 14 and it would become tightly coiled just before the rimsections reached the outer ends of the guideslots. Another stop-device of less desirable form consists of a flat piece which is secured in an aperture in the adjusting-disk 4 and projects from each face of the disk into the spiral groove near its inner end. A similar stop 21 projects into the spiral groove of the adjusting-disk 6, near its inner end. When the rim-sections 7 nearly reach the inner ends of the guide-slots the lowermost tooth on each end of one rim-section impinges against the sides of the stops 20 and 21, thereby preventing further rotation of the guide-plates upon the shaft. When the rim-sections of the drum 3 are shifted to their outermost position, those of the drum 2 are simultaneously shifted to their innermost position and one of them strikes the other end of the stop 20 and a similar stop on the other adjustingdisk, not shown, of this drum. Both of the stop devices shown and described may be employed in the same pulley and either of them may be employed in a single expansible pulley or in one having more than two drums. The precise means for effecting the relative rotation of the guide-plates and adjustingdisks is immaterial to the function of the i iaimsaid rotating-means, for arresting the relative rotation in both directions and at predetermined points, as set forth. Y

3. An expansible pulley, odmprisingrimsections, a guide-plate, an adjusting-disk, said plate and disk being relatively revoluble, and a stop consisting of a flexible strip having its ends attached to said plate and disk, as set forth.

4. An expansible pulley, comprising rimsections,. a guide-plate, an adjusting-disk, said plate and disk being relatively revoluble, and stops consisting of two flexible strips having their ends attached to said plate and. disk, as set forth.

5. An expansible pulley, comprising rimsections, a guide-plate, an adjusting-disk,

said plate and disk being. relatively revolu r ble, and a stop consisting of a flexible coiled strip having its ends attached to said plate and disk, as set forth. r

6. An expansible pulley, comprising'rim sections, a gu1de-plate, an admstihg-disk, said plate and disk being relatively revoluble, and stops consisting of two flexible coiled stripshaving their ends attachedto said'plate and disk, as set forth.

7. An expansible pulley, comprising rimsections having toothed ends, radially-slotted guide-plates and spirally-grooved adjusting-disks receiving the ends of said rimsections, said plates and disks being relatively revoluble, and a pair of oppositelycoiled flexible strips having their ends attached to a guide-plate and adjusting-disk, as set forth.

8. An expansible pulley, comprising ri msections having toothed ends, radially-slotted guide-disks and spirally-grooved adjusting-disks receiving the ends of said rim-sec tions, said plates and disks being relatively revoluble, a hub extending from an adjustingdisk, and a pair of oppositely-coiled flexible strips having their ends attached to a guideplate and said hub, as set forth.

In testimony whereof, I affix my signature in presence of two witnesses.

\ f CHARLES J. REED;

Witnesses:

EUGENE A. BYRNES, RoB'r. B. FLETCHER. 

